90 MINUTE STRUCTURE. [CHAP. 



CHAPTER VIII. 



THE MINUTE STRUCTURE AND VITAL PROCESSES OF 

 PLANTS. 



1. The minute parts of which plants are composed. 



2. The cells (of Rhubarb). 



3. The vessels (of Rhubarb and Oak). Their modifications. 



They originate from cells. 



4. Tissues for comparison with those of Rhubarb. 



5. Active cells contain fluid contents. 



6. Cell-wall and cell-contents. Cell-nucleus. Division and 



growth of cells. 



7. Colouring matter of leaves. Chlorophyll. 



8. Starch. Oil. Sugar. 



9. Crystals in cells. 



10. Long and short cells. Fibro-vascular system of plants. 



11. Comparison of the arrangement and mode of increase of 



fibro- vascular bundles in Monocotyledons and Dicotyle- 

 dons. The cambium cells. Exogenous and endogenous 

 stems. 



12. Woody Dicotyledons further examined. Pith ; wood ; 



medullary rays ; bark. 



13. Circulation of fluids through the tissues. Diffusion. 



14. The epidermis and its structure. Stomates. Intercellular 



spaces. 



i. TN our second chapter we inquired very briefly into 

 1. the functions of the nutritive organs. Now that 

 we have had the opportunity of comparing the corre- 

 sponding organs of many plants, and of forming some 

 tolerable idea of the extent to which the same organ may 

 vary, in external character, in different plants, it may 

 be worth while to examine more closely than was at 

 first expedient into their mode of working. In order to 



